A tight genetic linkage between the neurodegenerative disease amyotrophic lateral sclerosis (ALS) and the gene encoding Cu,Zn SOD has been recently reported. ALS, also known as Lou Gehrig's disease, is a late onset disease, marked by the degeneration of motor neurons which leads to progressive paralysis. It is a uniformly fatal disease, and effects 11,000,000 people. Thirteen point mutations in the Cu,Zn SOD gene have been identified from ALS patients. It is the linkage of the disease to the enzyme that motivates this study. These studies are aimed at elucidating the structural basis of the ALS point mutations in the Cu,Zn SOD enzyme.